The field of the invention pertains to hand held underwater weapons and, in particular, to underwater multishot spear guns. Such guns generally comprise a head having one or more firing chambers and a long shaft handle. The guns are carried by divers in waters where shark attack is a possibility. Shells are fired by impacting the head against the target, typically an umnderwater predator such as a shark.
Single chamber impact actuated guns are disclosed in U.S. Pat. No. 3,274,936, U.S. Pat. No. 3,664,052 and U.S. Pat. No. 4,100,692. These patents disclose various means for constructing the chamber and, in particular, the firing mechanism. Unfortunately, if the first shot is not successful, reloading underwater in sufficient time to avert disaster may not be possible.
Because of the need for repeat shots without reloading, multishot weapons have been developed. U.S. Pat. No. 3,616,561 discloses a multiple long bore gun wherein the barrels are rotatable in the manner of a long cylinder and the firing pin is trigger actuated. Such a gun is unduly complicated and unwieldy.
A multiple shot gun with a rotatable cylinder head for firing bullets is disclosed in U.S. Pat. No. 3,494,060. Impacting the head against a target causes firing of a bullet and indexing the next chamber and bullet into position. U.S. Pat. No. 3,545,117 and U.S. Pat. No. 3,721,031 each disclose rotatable cylinder heads with large chambers for shotgun shells and fired by impact. Although multiple shot capability is provided, the cylinders cannot easily be replaced underwater.
With a view toward a more convenient and effective multishot underwater gun wherein the cylinder can be easily exchanged underwater, applicant has invented the following device.